Oil atomizer for burners



Patented Apr. 14,. 1953 UNITED STATES PATENT OFFICE OIL ATGMIZER FORBURNERS Philip L Knight, Toledo, Ohio, assig'nor to Surface CombustionCorporation, Toledo, Ohio, a

corporation of Ohio Application May .22, 1948, S.erial.No.;28,5.83

1 `Claim.

pended thereto.

-In the accompanying drawingsrforming'part of lthis specication- Fig. lis an axial sectional view of the Aimproved oil converting devicewith anintermediate uportion broken away.

Fig. r2 is a cross section on line 2-2 of Fig. Vl.

Fig. 3 shows an alternative form of a part `ern-- bodied in Fig. 1.

Fig. 4 shows still another alternative form of a part embodied in Fig.1.

Fig. 5 shows a modiiied form of Fig. 2.

Figs. 6 to 9 each shows a different kind of gas Y burner with thepresent invention applied thereto.

In the present invention, the apparatus comprises arelatively slendertube or nozzle I0 from which the oil issues in a finely divided .statein a high velocity carrier stream of 4gaseous medium which willordinarily be air under pressure rather than steam because of its readyavailability. The tube I0 extends from a hollow head II to which airunder pressure is delivered by asupply .pipe I2 and to which oil isdelivered by a metering nozzle lI3 mounted in! an end wall of the head,.the oil being delivered to the nozzle under pressure by an oil supplypipe I4. The metering nozzle is of :conventional atomizing type .and theoil issues therefrom as a fine spray.

The metering nozzle I3 discharges into an :oil Acollecting barrel I5which ,in turn delivers to the said tube I0, the barrel being screwedinto the V .head II 'and having its inlet and terminating short of theend wall wherein Vthe metering noz- :zle is positioned. Because the oilissues ,from the Vsaid metering nozzle as a fine .spray it will bereadily appreciated that on striking the inner'wall .surface of thebarrel it tends to convert to a thin layer or film thereon and thereforethat it is the 'gaseous medium ilowing through said barrel I5 and tubeI0 with relatively high velocity that moves the'oil along said surfaceand along the inner surface ofthe tube I0. The space I6 within the headII to which the air supply pipe I2 delivers is annular and thereforeVthe air flows 2 Y into the intake Vend of the ibarrel .I5 byiinitiallyflowing across the rim thereof next adjacent the metering nozzle I3 andthereby tends to help in directing spray from said nozzle into saidbarrel.

Threads 2B on an exterior p-ortionof the head I I permitit to be securedto a support ,associated with the gas burner which is to be converted toburn oil. However, instead of the head itself being thus threaded, thethreads may be provided on an outwardly extended portion,2;| ofthebarrel I5 (see Fig. 4).

Bearing in mind that a gaseous propelling `medium for the oil must alsoilow through the tube I0, the oil feeding capacity of said tube, otherthings being equal, is directly dependent Von the lperimeter of the bore.of the tube rather .than

on the cross sectional area thereof. In .cases where the oil feedingcapacity of the said tube I0 is relatively small (as for vexample where`the bore of the tube has a diameter of about Vonesixteenth of an inchwhich may be taken to be the size of the bore of the tube I0 in Fig. 3)it is not necessary to provide any special flow restricting orifice atthe discharge end of the tube to insure that the oil shall be ejectedfrom the tube Vin nely divided state, primarily for the reason that in arelatively small tube the ycenter oi? the air stream is not sufficientlyremote from the oil film on the tube to permit any substantial lquan,-tity of the air to Yescape without exerting an atomizing effect `on theoil film as the latter is ejected from the tube. On the other hand, inthe larger size tubes ID, the greater is the quantity of air which tendsto escape from the ycenter of the air stream Without doing its quota ofwork on said lm of oil. To reduce this wastage of high pressure air to aminimum in the larger size tubes, the present invention provides adisk-.type

Y baffle or ,iller 22 vat the discharge -end of the tube whereby torestrict the lnormal .discharge area lof the tube to an annular type ofdischarge orice 23 of relatively narrow width. As shown in Fig.. 2, thesaid orice may consist of a circular series of relatively small sizeholes 24 or :as shown in Fig. 5 it may consist of a series of notches 25in the rim of the balle. vBy thus reducing the .escape of air from thecenter `of the airstream, only a relatively small proportion (say notmore than one-fth) of the air for complete combustion of the oil need bepassed through the oil tube I0 to obtain the necessary propelling andatomizing effect on the oil, it being understood that the additional airfor complete combustion being otherwise supplied as will more fullyappear hereinafter. It will also be understood that because the oilissues from the tube i already dispersed in a stream of air theresulting flame of combustion will be much shorter than would be thecase if steam instead of air were used to propel the oil through thetube.

The practical application of the invention is shown in Figs. 6 to 9. Ineach of these views a portion of the wall of an industrial furnace isindicated at 26, the wall comprising a refractory block 21 formed with acombustion tunnel 3!) to which the gas burner delivers.

In Fig. 6, a gas burner comprises a nozzle 3l from which the gas admixedwith its full complement of air for complete combustion is delivereddirectly to the combustion tunnel 30, the mixture being delivered tosaid nozzle by a tube 32 to which a mixture supply pipe 33 delivers. Apremix pilot is indicated at 34. To convert the burner over to oil, theoil tube I9 is inserted part way into the nozzle 3l by screwing the tubesupporting head Il into the outer end of a pipe T 35 which interconnectsthe burner tube 32 and the mixture supply pipe 33. The supplemental airfor complete combustion of the oil is delivered to the burner tube 32 bya supply line which will ordinarily comprise the pipe 33 and thenceflows to the combustion tunnel 30 by way of the burner nozzle 3l as willnow be readily understood.

In Fig. 7, the burner comprises a mixing tube 35 which dischargesdirectly into the combustion tunnel 30. To convert this burner over tooil, the oil tube l0 is inserted part way into the said mixing tube 35by screwing the extension 2i of the tube supporting head Il into thesupport 31 in place of the gas discharge nozzle which normallydischarges into the mouth of the mixing tube 36from said support. In aconverted gas burner of this type the tube I9 is small enough to permitthe necessary secondary air to be drawn into the mixing tube 36 aroundthe oil tube by the suction effect of the air and oil mixture issuingfrom the oil tube l0.

In Fig. 8, the burner comprises a mixing tube 4I!v set to discharge intothe combustion tunnel 30 across an intervening air space. To convertthis burner over to oil, the oil tube l0 is inserted into the saidmixing tube 40 by screwing the supporting head thereof into the support4l in place of the gas discharge nozzle. The necessary additional airfor complete combustion of the oil is drawn into the combustion tunnel30 by the velocity of the air stream from the tube l0 as it flowstowards the tunnel across the intervening air gap.

In Fig. 9, a gas burner comprises a mixing tube 42 which deliversdirectly to the combustion tunnel 30. A premix pilot is indicated at 43.The air-gas mixture is formed by delivering air under pressure to themouth of the mixing tube and by delivering gas at atmospheric pressureabout the tube for ow thereinto through radial gas inlet ports 44intermediate the ends of the tube. The gas supply pipe is indicated at45, the same delivering to a chamber formed by a casing 46 around themixing tube proper. The air supply pipe is indicated at 47l the Same d6-vlivering to the mixing tube by wayv of a passage tively simple Vandpractical method and apparatus for atomizing oil for burners and whichis very useful in converting many types of gas burners overrto oil.Certain of the apparatus herein disclosedV but not claimed is disclosedandclaimed in my application Serial No. 15,326 filed March 17, 1948, nowPatent No. 2,518,025, granted August 8, 1950.

What I claim is:

A device for use with burners comprising, in combination, a hollow headdefining a chamber for gaseous medium Linder pressure, an oil inlet tosaid chamber consisting of a metering nozzle of the atomizing type fordischarging oil into said chamber in a fine spray, and an imperforateoil conducting tube having an inlet end, an outlet end, a relativelyunrestricted tube passage therebetween and at its outlet end at leastone relatively small discharge orice,'said tube being mounted on saidhead axially aligned with and spaced from said metering nozzle toreceive oil therefrom and gaseous medium from said chamber, whereby saidoil is substantially converted to a film within said tube, propelled assuch through the passage thereof and atomized upon discharge therefromby said gaseous medium as it passes through said discharge orifice.

PHILIP L. KNIGHT.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 275,124 Blumenberg et al. Apr. 3, 1883 370,251 Field Sept. 20,1887 760,729 Camp May 24, 1994 818,030 Kirkwood Apr. 17, 1906 910,267Billow Jan. 19, 1909 1,061,627 Nice May 13, 1913 1,241,135 VMastenbrool:Sept. 25, 1917 1,304,402 Spire May 20, 1919 1,400,657 Brodie Dec. 20,1921 1,636,597 Fischer et al. July 19, 1927 1,659,573 Lalor Feb. 21,1923 1,663,045 Gibson Mar. 20, 1928 1,712,326 Brock May 7, 19291,754,828 KelsallY Apr. 15, 1930 1,797,570 Ferguson Mar. 24, 19311,799,459 Fantz Apr. 7, 193.1 1,826,776 Gunther Oct. 13, 1931 1,860,942Morse May 31, 1932 2,283,658 Westcott et al May 19, 1942 2,333,531Ferguson Nov. 2, 1943 2,518,025 Knight Aug. 8,. 1950

